User`s manual

108 Microtek ScanWizard Pro for Mac OS X
Threshold tool (Line Art images only)
Check this box if you wish
to sharpen your Line Art
image
Aside from dragging the
sliders, you can also enter a
value in the Threshold edit
box to change the Threshold
Drag the slider to change the Threshold.
• To darken the original, drag the slider to the right. This
increases the Threshold value so that more pixels are
turned to black, resulting in a darker image.
• To lighten the original, drag the slider to the left. This
lowers the Threshold value so that more pixels are turned
to white, resulting in a lighter image.
For Line Art images, the only AIC tool available is the Threshold tool.
Threshold is the dividing line between black and white; the range is 0 to 255,
and the default is 128. Thus, gray levels below the Threshold are converted to
black, while gray levels equal to or above the Threshold are converted to white,
resulting in a high-contrast, black-and-white representation of the image.